<template>
  <view>
    <view class="search-box">
      <uni-search-bar placeholder="请输入搜索内容" :radius="100" @input="input" cancelButton="none" clearButton="auto">
      </uni-search-bar>
    </view>

    <!-- 搜索建议列表 -->
    <view class="sugg-list" v-if="searchResults.length !== 0">
      <view class="sugg-item" v-for="(item, index) in searchResults" :key="index" @click="gotoDetail(item)"> 
        <view class="goods-name">{{item.goods_name}}</view>
        <uni-icons type="arrowright" size="16"></uni-icons>
      </view>
    </view>

    <!-- 搜索历史 -->
    <view class="history-box" v-else>
      <!-- 标题区域 -->
      <view class="history-title">
        <text>搜索历史</text>
        <uni-icons type="trash" size="17" @click="clean"></uni-icons>
      </view>
      <!-- 列表区域 -->
      <view class="history-list">
        <uni-tag :text="item" type="error" v-for="(item, index) in histories" :key="index" @click="gotoGoodsList(item)"></uni-tag>
      </view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        // 延时器
        timer: null,
        // 搜索关键词
        kw: '',
        // 搜索的结果列表
        searchResults: [],
        // 搜索历史列表
        historyList: ['b', 'baa', 'banner']
      };
    },
    onLoad() {
      // JSON.parse() 将数据转换为 JavaScript 对象
      this.historyList = uni.getStorageSync('kw') || []
    },
    methods: {
      // input 输入事件
      input(value) {
        
        // console.log(value);
        // 如果用户触发 input 事件 500 毫秒内再次触发 input 事件，则清空定时器
        clearTimeout(this.timer)
        // 如果用户触发 input 事件 500 毫秒内没有再次触发，则执行定时器的回调函数
        this.timer = setTimeout(() => {
          // console.log(11111111111)
          this.kw = value
          this.getSearchList()
        }, 5000)
      },

      async getSearchList() {
        // 判断是否为空
        if (this.kw.length === 0) {
          this.searchResults = []
          return
        }

        const {
          data: res
        } = await uni.$http.get('/api/public/v1/goods/qsearch', {
          query: this.kw
        })
        if (res.meta.status !== 200) return uni.$showMsg()
        this.searchResults = res.message
        
        this.saveSearchHistory()
      },

      gotoDetail(item) {
        // console.log(item.goods_id);
        uni.navigateTo({
          url: '/subpkg/goods_detail/goods_detail?goods_id=' + item.goods_id
        })
      },
      
      saveSearchHistory() {
        // this.historyList.push(this.kw)
        
        const set = new Set(this.historyList)
        set.delete(this.kw)
        set.add(this.kw) 
        // console.log(set); 
        this.historyList = Array.from(set)
        
        // 对搜索数据进行持久化存储
        // JSON.stringify() 转换为 JSON 字符串。
        uni.setStorageSync('kw', this.historyList)
      },
      
      clean() {
        this.historyList = []
        uni.setStorageSync('kw', [])
      },
      
      gotoGoodsList(item) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?query=' + item
        })
      }
    },
    computed: {
      histories() {
        // 将 historyList 数组使用展开运算符展开，并使用 [] 包裹从而生成一个新数组
        return [...this.historyList].reverse()
      }
    }
  }
</script>

<style lang="scss">
  .search-box {
    position: sticky;
    top: 0;
    z-index: 999;
  }

  .sugg-list {
    padding: 0 5px;

    .sugg-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 12px;
      padding: 13px 0;
      border-bottom: 1px solid #efefef;

      .goods-name {
        // 文字不允许换行
        white-space: nowrap;
        overflow: hidden;
        // 超出文本用 ... 代替
        text-overflow: ellipsis;
        margin-right: 3px;
      }
    }
  }

  .history-box {
    padding: 0 5px;

    .history-title {
      display: flex;
      justify-content: space-between;
      height: 40px;
      align-items: center;
      font-size: 13px;
      border-bottom: 1px solid #efefef;

    }

    .history-list {
      display: flex;
      flex-wrap: wrap;

      .uni-tag {
        margin-top: 5px;
        margin-right: 5px;
      }
    }
  }
</style>
